Gas turbine engines generally include a turbine section downstream of a combustion section that is rotatable with a compressor section to rotate and operate the gas turbine engine to generate power, such as propulsive thrust. General gas turbine engine design criteria often include conflicting criteria that must be balanced or compromised, including increasing fuel efficiency, operational efficiency, and/or power output while maintaining or reducing weight, part count, and/or packaging (i.e. axial and/or radial dimensions of the engine).
Interdigitated turbine sections are known to take advantage of relatively high fluid velocities between sequential stages of rotating airfoils without vanes therebetween. However, known interdigitated turbine sections are limited to interdigitated a low pressure turbine rotor and an intermediate pressure turbine rotor. Still further, known interdigitated turbine sections are limited by axial, radial, thermal, and/or mechanical loads from the inner radii of the interdigitated turbine sections, which may limit a quantity of stages that may be included in an interdigitated first turbine rotor.
Therefore, there exists a need for a structure that may reduce or remove limits to interdigitated first turbine rotor size and structural life due to axial, radial, thermal, and/or mechanical loads.